Method of metallurgical filtration.



UNITED STATES PATENT onn on.

PERCY A. BOEGK, LOS ANGELES, CALIFORNIA, ASSIGNOR TO CELITE PRODUCTSCOM- PANY, OF LOS ANGELES, CALIFORNIA, A CORPORATION OF CALIFORNIA.

METHOD OF METALLURGICAL FILTRATION.

No Drawing.

To all whom it may concern:

Be it known that I, PERCY A. BOECK, a citizen of the United States,residing at LosAngeles, in the county of ,Los Angeles and State ofCalifornia, have invented a new and usefulMethod ofMetallurgicalFiltration, of which the following is a specification.

This invention relates to a method of filtering solutions or slimescontaining mineral matter in suspension, and the main object of theinvention is to facilitate the separation from such solutions, of veryfinely divided mineral matter which is liable in such manner that thekieselguhr is enabled to maintain the open condition-of the deposit onthe filterysurface, as the solid material accumulates thereon.-

My invention is preferably carried outas follows: The kieselguhr, inmassive condition, as it comes from the quarries, or crushed to anydeslredsize, is incorporated with the body of mineral being treatedpreferably during the crushing of the mineral, or .the reduction thereofto a finely divided state'by grinding or otherwise, so that the.kieselguhr is crushedor ground along with the'mineral and becomes moreor less mixed therewith during the crushing and agitation thereof. Themineral matter, together with quent mixing and, agitating operation,

a liquid required for treatment of the mineral, and the slimes orso1utioncontain-. ing the mineral matter and the finely divided thekieselguhr, is mixed, either during the crushing or grinding operation,or by a subsei-1 wit kieselguhr in suspension is then assed to asuitable filter, wherein the liquid 15 extracted or removed from thesolid matter, the kieselguhr being retainedin or on the filter alongwith the other solid matter and servin to maintain the porosity of thecake or be of solid material during the filtering operation.

The mixing of t e kieselguhr with the Specification of Letters Patent.

.agitator used in leaching operations.

Patented Nov. 6, 1917.

Application filed November 3, 1914. Serial No; 870,164.

slimes, or body of mineral and liquid to be treated, may be carried outotherwise than as above described. For example, the kieselguhrmay becrushed or ground to a state of fine division before introduction intothe body of mineral and liquid, and may be mixed with such mineral andliquid by agia tation therewith, for example, in the usual in somecases, the finely divided kieselguhr may be mixed with the solution orslimes after the. latter is drawn ofi' from the agita tor and before itis filtered.

My improved method of filtration may be applied in connection with acyaniding process, as follows: The kieselguhr may be incorporated intothe body of ore during the crushing thereof, or crushed along therewith,as above stated, and the mixture of ore and kieselguhr then introducedinto the usual agitator, wherein the ore'is subjected to the action ofcyanid solution, in the usual manner, the mixture being agitated asusual .and vthis agitation resulting in a further mixing .ordistribution of the kieselguhrv in the body of mineral and solution. Thepres ence of the kieselguhr in the body of liquid and mineral at thistime is also of advantage in that it facilitates the leaching action, by

keeping the mineral distributed or open for accessof the solvent;

The liquid is drawn off from the agitator, with or without decantation,as may be de, sired, such liquid containing the dissolved mineral valuesand more or less of theinsoluble matter in suspension, and is filteredin any suitable apparatus, for example, a filter press, and in thisoperation the more or less finely divided kieselguhr passes to thefilter press along with the other insoluble mineral matter and isdeposited on the'filteringsurface along with such mineral matter. It isa distinctive quality of, the kiesel-' guhr that'it is inherentlyporous, that is to say, each particle thereof is porous,'.and as thekieselguhr is distributed throughout the mineral mass deposited on thefilter surface and between the particles of slime or gang'ue, itmaintains the porosity of the mass as a whole, and prevents or at least,greatly retards, the clogging of the filter surface by the slimes .or'fine particles of gangue. As 1 the solid mineral material accumulates onthe filter surface, the kieselguhr accumulates'along therewith, andmaintains the openness of the bed or cake, and also expedltes theformation of a cake of proper thickness for efi'ective filtration.

The amount of kieselguhr used will dev used in connection with eithergravity,

pressure or vacuum filtration. The method is especially advantageous inpressure filtra: tion, the use of kieselguhr 1n suchan operation servingto reduce the time of forming a filter cake of proper thickness andquality, as much'as twenty-five per cent., and also increasing therecovery of values from the cake as much as fifteen per cent. The use ofkieselguhr. has an especlal advantage Where air treatment is required inthe filter press,

the kieselguhr serving to hold the air in the cake and enabling the sameto-- pass uniformly through the cake Without causing air-cracks. Italsoenables more effective re- .moval of the values from the cage by(lisplacement of the solution. by Water or otherwise.

It is an important feature of my invention that the kieselguhr used as ameans for aiding filtration is nearly pure silica. and is chemicallyinert with reference to the substances to be-filtered. It therefore doesnot interfere With the action of the leaching agent in any Way or affectthe chemical condition of the lixiviate. I 1

What I claim is:

1. The method of treating ores, which consists of forming a mixture ofdivided ore and divided inert, porous, mineral material, together with aleaching liquid, and filtering such mixture. p

2. The method of treating ore, which consists in forming a mixture offinely divided ore and kieselguhr, together with a liquid for dissolvingthe values in" the ore, and then filtering such mixture.

In testimony whereof I have hereunto set my hand, at Los Angeles,California, this 21st day of October, 1914.

. PERCY A. BOECK.

Witnesses:

W. DIETERLE, A. W. KNIGHT.

Correction in Letters Patent No. 1,245,557.

It is hereby certified that in Letters Patent No. 1,245,557, grantedNovember 6,

1917, upon the application of Percy Boeck, of Los Angeles, California,for an improvement in "Methods of Metallurgical Filtration, an errorappeers in the printed specification requiring correction as follows:Page 2, line 28, for the word cage read cake; and that the said LettersPatent should be read with this correction therein that the same mayconform to the, record of the case in the Patent Ofiioe.

Signed and sealed this 5th day of March, A. D., 1918. i

R. F. WHITEHEAD, Acting Commissioner qfPtmnte.

[sun] Cl. 75 l8.

